Hello,

I will be getting American Walnut, 3/4'' thick, 3'' wide, hand-scraped floors installed. the installers said they use basic rosin paper as the barrier under the new floor. It is being installed on plywood on the first floor, a basement is below. Is the rosin paper good enough or should I upgrade to the black paper. I would really just like to avoid creaking.

What is recommended?

Black 15 lb.felt is what's recommended for 3/4" flooring.

Rosin paper is crap and not a moisture barrier do not let them use it. Get Aquabar-b from Home Depot found with the hardwood flooring it is a 15lb felt but much cleaner to use then black roofing felt

Ditto on the Aquabar B. The moisture barrier won't stop squeaks. It's the floor boards rubbing against each other or the subfloor joints rubbing.

+1 on the Aquabar B. I installed a floor about 7 years ago with it, and today that floor is just like when I installed it. It's perfect.

The part of the house that I hired out was done with red rosin paper. Same wood, same finish... disaster. Gaps, creaks, you name it. Get the Aquabar.

It is not really a moisture barrier, but a moisture retarder. Slows down the amount of moisture vapors passing through it.

A true moisture barrier would be a plastic film with a high perm rating.(you don't want that over wood subfloor)

Basements being known to have a higher level of humidity than the upper levels above grade, rosin paper would not be my choice. Black asphalt impregnated felt paper(roofing felt) would be my go to, slip sheet.